Global Warming Biggest Health Threat of 21st Century, Experts Say

WEDNESDAY, May 13 (HealthDay News) -- The warming of planet Earth is "the biggest global health threat of the 21st century," a varied group of experts warned Wednesday.

Their report is one of the latest to expound on the deepening environmental crisis, and one of the first to focus on the potential role of health-care professionals in ameliorating the problem.

"This is a bad diagnosis not just for children in different lands. It's for our children and grandchildren," Anthony Costello, a professor of international child health and director of the Institute for Global Health at University College London, said during a Wednesday teleconference. "Even the most conservative estimates are profoundly disturbing and demand action. Climate change raises an important issue of intergenerational justice, that we are setting up a world for our children and grandchildren that may be extremely frightening and turbulent."

Costello is lead author of a thick report produced jointly by The Lancet journal and University College London (UCL) and published in the May 16 issue of the journal.

"There are no institutions at the global level who can really deal effectively with devising complex solutions to these complex problems," added Lancet editor Dr. Richard Horton. "It is an urgent threat. It is a dangerous threat. It has been neglected, and requires an unprecedented response by governments and international organizations."

Among other things, the report's authors call for the involvement of health professionals, who have not yet been central to the cause.

Climate change is now a fact of life on this planet.

"The vast majority of experts, 95 percent, maybe even 99 percent, agree that global warming is taking place," said Kirby Donnelly, head of environmental and occupational health at Texas A&M Health Science Center School of Rural Public Health. "The big issue is the model: When will global warming become a problem?"

The report based its predictions on a 2- to 6-degree warming over the next century but focusing on a pessimistic 4-degree rise, said Mark Maslin, director of UCL's Environment Institute.

Among the health consequences of such a rise:

Vector-borne diseases such as dengue fever and malaria, once confined to warmer areas, will move north and become more widespread as a result of increased temperatures.

Heat waves will kill more people in more areas of the world (more than 70,000 people died during a heat wave in Europe in 2003).

Crop yields will decline, leading to greater food insecurity in a world where 800 million already go to bed hungry every night.

Water shortages will lead to more gastroenteritis and malnutrition, among other health problems.

Extreme climactic events such as flash flooding due to changing rainfall patterns and melting ice sheets will hinder the world's sewage systems, leading to diarrhea and other problems, said Dr. Hugh Montgomery, director of UCL's Institute for Human Health and Performance. Severe cyclones and hurricanes will also take more lives.

More people living in cities will lead to a shortage of housing, which will lead to slums, which will lead to inadequate sanitation systems and increased vulnerability to extreme weather events.

The authors propose adopting policies to reduce carbon emissions and increase carbon biosequestration and to equalize the world's health systems, among other recommendations.

"We have a moral dilemma: How do we protect the health of the poorest people in the world and allow them to develop," Maslin said.

"There are so many public health issues associated with global warming that certainly, once it becomes a significant problem, it will be the most significant public health problem at that point in time," Donnelly said.

"This is a problem that affects the entire planet, and the longer it takes 'us,' the people on this planet, to take action, the more difficult it will be to resolve the problem," Donnelly said. "We urgently need to take at least minimal action to try to reduce emissions and move toward taking more significant action to reduce global warming."